In the past year, a laboratory has been organized to study problems in Urologic Oncology in the Surgery Branch of the National Cancer Institute. A variety of problems related to cancer of the urogenital system are being addressed. Studies in humans and animal models of the metabolic abnormalities associated with prostatic cancer are in progress. The etiology and metabolic basis for osteomalacia in patients and in animals with prostate cancer are being evaluated. The factors controlling the growth of prostatic cancer both in vivo and in tissue culture are being studied. In addition, studies have begun investigating the endocrine responsiveness of bladder cancer and on the influence of LHRH agonists on the growth of a hypercalcemia producing rat lytic cell tumor of the testis.